Endoscopes have been used for many years for viewing within a desired region of a patient's body through the patient's airway, other natural orifices, or a surgical incision. An endoscope typically has an elongated flexible shaft with a control head at its proximal end. The flexible shaft is equipped with one or more functional channels (e.g., instrument channels, air channels, irrigation channels, suction channels) that extend along the length of the flexible shaft from the distal end to the control head. The control head is connected to a light source, air/water supply and suction via an “umbilical” cord.
For fiber-optic endoscopes, the flexible shaft is also equipped with a channel holding optical fibers (i.e., an image guide) for carrying an image from the distal end of the shaft to the control head, where it can be viewed through an eyepiece by a physician.
For video-endoscopes, a Charge Coupled Device (CCD), which serves as an image-capturing means, is located at the distal end of the endoscope. Captured images are compressed and recorded on, for example, a hard disk, a removable memory device, an optical disk, or a magneto-optical (MO) disk.
The tip of the endoscope is controlled using pull wires attached at the tip just beneath the surface of the flexible shaft, and passing back through the length of the shaft to angling controls in the control head of the endoscope. Two angling wheels or knobs located on the control head for up/down and right/left movement incorporate a friction braking system, so that the tip can be fixed temporarily in any desired position.
Surgeons in the past have used blunt-tipped instruments as well as balloons in connection with endoscopic surgery to dissect tissue in order to develop a working space in the interior of the body. Balloon type surgical instruments have been developed to assist in this regard. Several of these prior art instruments are described below.
U.S. Pat. No. 5,762,604 describes a surgical instrument that utilizes an inflatable, transparent balloon. The instrument serves to dissect and form a dissected viewing space within the interior of the body to provide adequate depth of field for endoscopic viewing. The instrument includes a transparent tipped dissector-guide 5 having a guide member 10 with an interior lumen (cavity) 14 (dimensioned to accommodate a viewing scope or endoscope 22) as well as a working channel 34 (for an elongate trocar). The guide member 10 affords the surgeon contemporaneous vision through the far end of the guide 10 as the instrument navigates the interior of the body. Metal band 132 and balloon constraining sleeve 133 are employed to constrain balloon 120 in a first collapsed position around guide member 10. The constraining sleeve 133 is provided with a weakened, perforated surface that will give way and burst when an inflation medium is introduced into balloon chamber 122 allowing the balloon to deploy to the inflated position. As the balloon inflates, tissue is dissected by the balloon generally applying forces perpendicular to the tissue being dissected or separated. When balloon 120 is inflated, it is disposed in a “hot dog bun” shape around the guide 10, offering increased depth of field in all directions around lens 32 of endoscope 22. Procedures are described in this patent as being performed on an outer surface of the inflated balloon. See e.g., Cols. 7 to 8, lines 60 to 3, of the '604 patent.
U.S. Pat. Nos. 5,607,441 and 5,707,382 both describe a surgical instrument that includes an assembly 10 consisting of two primary components, namely, a balloon dissector 11 for the dissection of internal bodily tissue to form an operative space during a surgical procedure, and an endoscope 12 for providing simultaneous visualization during the surgical procedure as the dissector is advanced through tissue and the operative space is formed. The balloon dissector 11 basically comprises a conventional trocar cannula 13, an extension assembly 14 (with transparent tissue-contacting element 24), and an inflatable balloon 15. Tubular sleeve 17 connects trocar cannula 13 and extension assembly 14 and is sized to receive an endoscope. An endoscope would be inserted distally in assembly 10 through tubular sleeve 17 until it abuts ring 23 at the distal end of the extension assembly 14. Use of assembly 10 is described in Cols. 5 to 6, lines 55 to 19, of the '382 patent, and is shown in FIGS. 3 to 5, of this patent. To summarize, once the assembly 10 is positioned parallel to adjacent tissue layers with the aid of the endoscope, the balloon 15 is inflated to form an operative space. The balloon 15 is then deflated, and the assembly including the balloon dissector 11 removed and another trocar cannula 35 introduced into the operative space.
U.S. Pat. Nos. 5,938,585 and 6,277,065 both describe an anchoring and positioning balloon device shaped like a cradle that is deployed using a side-view type endoscope 10. Endoscope 10 includes an illumination device 20, a viewing device 22, and a working lumen or channel 24, all contained within window section 18. A cradle shaped inflatable balloon 30 is attached to the distal end section 12 of the endoscope 10. During operation of the endoscope 10 with the balloon 30 inflated, the cradle portion 34 spaces the window section 18 from the examining area, thus providing a good view of and a sufficient working space relative to the body cavity wall 27 (see Cols. 3 to 4, lines 59 to 7, of the '065 patent).
US 2005/0159645 A1 describes a sheath for use with a medical device such as an endoscope, that comprises: an elongated body having a proximal end and a distal end; a main lumen extending through the elongated body from the proximal end to the distal end; and one or more inflatable balloons mounted on an outside surface of the elongated body proximate to the distal end. Embodiments employing multiple balloons mount the balloons 16, 18, 52, 54, 56 in isolated fashion on the distal end of the elongated body (see FIGS. 1A, 1B, 1C), or along the length of the elongated body (see FIGS. 4A and 4B).
Unfortunately, the use of single balloons or multiple isolated balloons on the distal end of these prior art devices renders the positioning and advancement of the devices between/through natural tissue planes difficult to control.
It is therefore an object of the present invention to provide an endoscope device capable of blunt dissection that allows for improved control over the positioning of the distal end of the device's shaft between natural tissue planes (e.g., subcutaneous, subfascial, intraperitoneal, intrathoracic, intracranial tissue planes) and further allows for improved control over the shaft's advancement through these tissue planes.
The present invention therefore provides an endoscope device that comprises a shaft having a distal end and a plurality of separately inflatable balloons that alone or together with exterior functional channels (e.g., instrument channels, air channels, water channels, suction channels) circumferentially surround the distal end of the shaft.
In a preferred embodiment, the inventive endoscope device comprises: a shaft made up of a flexible or partially flexible tubular member having a distal end, and interior optical and inflation channels extending there through; functional channels adapted to extend along an outer surface of the tubular member; and a plurality of separately inflatable balloons, where the balloons together with the exterior functional channels circumferentially surround the distal end of the tubular member.
The present invention further provides a method of dissecting layers of tissue to form a working space between the tissue layers and then performing an endoscopic procedure within the newly formed working space, which method comprises:                providing an endoscope device as described hereinabove, wherein the balloons located on the distal end of the device's shaft are fully deflated;        inserting the distal end of the shaft between the layers of tissue;        advancing the distal end of the shaft between the tissue layers by sequentially inflating and deflating various balloons until a desired length of dissection has been completed;        inflating all or some of the balloons to form a working space between the tissue layers; and        repositioning the distal end of the shaft within the newly formed working space, as necessary, while performing an endoscopic procedure therein by inflating and deflating various balloons.        
Other features and advantages of the invention will be apparent to one of ordinary skill from the following detailed description and accompanying drawings. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. All publications, patent applications, patents and other references mentioned herein are incorporated by reference in their entirety. In case of conflict, the present specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting.